Workshop to Obtain Input on Draft Materials for the Integrated Science Assessment (ISA) for Sulfur Oxides (SOx): Health Criteria

Background

Summary of Information About the Workshop

Section 109(d) of the Clean Air Act (CAA) requires the U.S. EPA to conduct periodic reviews of the air quality criteria for each air pollutant listed under section 108 of the Act.  Based on such reviews, EPA is to retain or revise the NAAQS for a given pollutant as appropriate.  As part of these reviews, NCEA assesses newly available scientific information and develops ISA documents (formerly known as Air Quality Criteria Documents) that provide the scientific basis for the reviews of the NAAQS.

NCEA is holding this teleconference workshop to inform the Agency’s evaluation of the scientific evidence for the review of the primary NAAQS for SO₂.  Section 109(b)(1) of the CAA defines primary NAAQS as standards, “the attainment and maintenance of which in the judgment of the Administrator, based on such criteria and allowing an adequate margin of safety, are requisite to protect the public health.”  EPA intends to develop a separate ISA, and NAAQS review, for the secondary (welfare-based) NAAQS for SO_X, in conjunction with a review of the secondary NAAQS for oxides of nitrogen.  The purpose of the workshop is to obtain peer input on the scientific content of preliminary draft materials that will inform the development of the draft health effects ISA.  Workshop participants will review and discuss preliminary draft materials on the atmospheric chemistry of and human exposure to SO_X as well as health effects evidence from in vivo and in vitro animal toxicology, controlled human exposure, and epidemiology studies.  In addition, panel discussions will help identify key studies or concepts within each discipline to assist EPA in integrating relevant literature within and across disciplines.  These preliminary materials are not being released to the general public before the workshop but will be used during the teleconference to guide workshop discussions and inform the development of the draft health effects ISA.  This workshop is planned to help ensure that the ISA, once developed, is up-to-date and focuses on the key evidence to inform the scientific understanding for the review of the primary NAAQS for SO₂.